[CLEANUP] update prettier to v2.0.4

package.json

@@ -49,7 +49,7 @@
     "jest-environment-jsdom": "^24.7.1",
     "live-server": "^1.2.1",
     "npm-run-all": "^4.1.5",
-    "prettier": "^1.19.1",
+    "prettier": "^2.0.4",
     "rollup": "^1.6.0",
     "rollup-plugin-typescript2": "^0.20.1",
     "sass": "^1.16.1",
@@ -78,6 +78,7 @@
     ]
   },
   "prettier": {
-    "printWidth": 100
+    "printWidth": 100,
+    "endOfLine": "auto"
   }
 }